Cannot competely disable documentation

[unknown321]

Bug report

Describe the bug

My goal is to create minimal mpd build, which will be running as a server in Docker. Even though documentation options are set to disabled, some docs are still there:

$ meson setup . output/release --buildtype=release -Db_ndebug=false \ 
    --prefix=/mpd \
    -Ddocumentation=disabled \
    -Dhtml_manual=false \
    -Dmanpages=false \
    -Ddoxygen=false \
    -Dsyslog=disabled \
    -Ddaemon=true \
    -Dsystemd=disabled \
    -Dlibfuzzer=false

...
mpd 0.25

  Subprojects
    expat        : YES
    fmt          : YES
    nlohmann_json: YES

  User defined options
    b_ndebug     : false
    buildtype    : release
    daemon       : true
    documentation: disabled
    doxygen      : false
    html_manual  : false
    libfuzzer    : false
    manpages     : false
    prefix       : /mpd
    syslog       : disabled
    systemd      : disabled

$ ninja -C output/release
$ ninja -C output/release install
ninja: entering directory 'output/release'
[1/4] Generating GitVersion.cxx with a custom command
[2/2] Installing files
Installing subdir /MPD/subprojects/fmt-12.0.0/include to /mpd/include
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/ostream.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/chrono.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/ranges.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/color.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/format-inl.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/base.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/compile.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/std.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/core.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/args.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/format.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/os.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/xchar.h to /mpd/include/fmt
Installing /MPD/subprojects/fmt-12.0.0/include/fmt/printf.h to /mpd/include/fmt
Installing subprojects/fmt-12.0.0/libfmt.a to /mpd/lib
Installing subprojects/expat-2.7.3/libexpat.a to /mpd/lib
Installing mpd to /mpd/bin
Installing /MPD/subprojects/expat-2.7.3/lib/expat.h to /mpd/include
Installing /MPD/subprojects/expat-2.7.3/lib/expat_external.h to /mpd/include
Installing /MPD/output/release/subprojects/expat-2.7.3/expat_config.h to /mpd/include
Installing /MPD/output/release/meson-private/fmt.pc to /mpd/lib/pkgconfig
Installing /MPD/output/release/meson-private/expat.pc to /mpd/lib/pkgconfig
Installing /MPD/mpd.svg to /mpd/share/icons/hicolor/scalable/apps
Installing /MPD/AUTHORS to /mpd/share/doc/mpd
Installing /MPD/COPYING to /mpd/share/doc/mpd
Installing /MPD/NEWS to /mpd/share/doc/mpd
Installing /MPD/README.md to /mpd/share/doc/mpd

Expected Behavior

No files in /mpd/share/doc

Actual Behavior

Installing /MPD/AUTHORS to /mpd/share/doc/mpd
Installing /MPD/COPYING to /mpd/share/doc/mpd
Installing /MPD/NEWS to /mpd/share/doc/mpd
Installing /MPD/README.md to /mpd/share/doc/mpd

Version

/mpd/bin/mpd --version
Music Player Daemon 0.25 (v0.24.6-130-ge5df578e2)

This is not a big deal, I can remove files manually, but is this intended behaviour?

[MaxKellermann]

The documentation option is described as "Build documentation", and indeed no documentation is being built. This option is not about whether documentation is getting installed.
So yes, this is intended behavior.
If you want to exclude these files from your Docker image, delete them after the installation. (But mind that distributing such an image without a copy of the license may be a copyright violation.)